Letters to Nature

Nature 418, 859-862 (22 August 2002) | doi:10.1038/nature00980; Received 8 April 2002; Accepted 9 July 2002

Chemical investigation of hassium (element 108)

Ch. E. Düllmann1,2, W. Brüchle3, R. Dressler2, K. Eberhardt4, B. Eichler2, R. Eichler2, H. W. Gäggeler1,2, T. N. Ginter5, F. Glaus2, K. E. Gregorich5, D. C. Hoffman5,6, E. Jäger3, D. T. Jost2, U. W. Kirbach5, D. M. Lee5, H. Nitsche5,6, J. B. Patin5,6, V. Pershina3, D. Piguet2, Z. Qin7, M. Schädel3, B. Schausten3, E. Schimpf3, H.-J. Schött3, S. Soverna1,2, R. Sudowe5, P. Thörle4, S. N. Timokhin8, N. Trautmann4, A. Türler9, A. Vahle10, G. Wirth3, A. B. Yakushev8 & P. M. Zielinski5

  1. Departement für Chemie und Biochemie, Universität Bern, CH-3012 Bern, Switzerland
  2. Labor für Radio- und Umweltchemie, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
  3. Gesellschaft für Schwerionenforschung mbH, D-64291 Darmstadt, Germany
  4. Institut für Kernchemie, Universität Mainz, D-55128 Mainz, Germany
  5. Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
  6. Department of Chemistry, University of California, Berkeley, California 94720-1460, USA
  7. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, P.R. China
  8. Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna, Russia
  9. Institut für Radiochemie, Technische Universität München, D-85748 Garching, Germany
  10. Research Center Rossendorf e.V., D-01314 Dresden, Germany

Correspondence to: H. W. Gäggeler1,2 Correspondence and requests for materials should be addressed to H.W.G. (e-mail: Email: gaeggeler@iac.unibe.ch).

The periodic table provides a classification of the chemical properties of the elements. But for the heaviest elements, the transactinides, this role of the periodic table reaches its limits because increasingly strong relativistic effects on the valence electron shells can induce deviations from known trends in chemical properties1, 2, 3, 4. In the case of the first two transactinides, elements 104 and 105, relativistic effects do indeed influence their chemical properties5, whereas elements 106 and 107 both behave as expected from their position within the periodic table6, 7. Here we report the chemical separation and characterization of only seven detected atoms of element 108 (hassium, Hs), which were generated as isotopes 269Hs (refs 8, 9) and 270Hs (ref. 10) in the fusion reaction between 26Mg and 248Cm. The hassium atoms are immediately oxidized to a highly volatile oxide, presumably HsO4, for which we determine an enthalpy of adsorption on our detector surface that is comparable to the adsorption enthalpy determined under identical conditions for the osmium oxide OsO4. These results provide evidence that the chemical properties of hassium and its lighter homologue osmium are similar, thus confirming that hassium exhibits properties as expected from its position in group 8 of the periodic table.